Disclosed are an aligning roller bearing with a middle retaining ring and a two-row roller bearing. The aligning roller bearing with the middle retaining ring comprises: an inner ring, an outer ring, a holding support arranged between the inner and outer rings, two rows of rollers arranged in the holding support and between the inner and outer rings, and the middle retaining ring arranged along the inner side of the outer ring and between the two rows of rollers. At least one oil filling hole is arranged at the middle part of the outer ring and radically passes through the outer ring. A cross section of the middle retaining ring is of a V-shaped structure, the opening of which faces the at least one oil filling hole. When lubricating grease is injected through a grease filling hole, the injected lubricating grease is brought into the inner part of the middle retaining ring, enters inner V-shaped space with rotation of the middle retaining ring, and flows into a rolling channel of the bearing. Therefore, difficulty of the whole grease filling process is greatly reduced.